What is the difference between different colors of antifreeze?
2 Answers
Different colors of antifreeze are used to distinguish it from other liquids and do not have any other special functional purposes. They also help users differentiate when selecting antifreeze to prevent mixing different types of antifreeze, which could damage the engine. The main components of antifreeze are ethylene glycol, propylene glycol, and diethylene glycol. Ethylene glycol is generally green, propylene glycol is red with a hint of orange, and diethylene glycol is blue. The full name of antifreeze should be antifreeze coolant, meaning it is a coolant with antifreeze properties. Antifreeze prevents the coolant from freezing and cracking the radiator or damaging the engine cylinder block or head during cold winter parking. Many people think antifreeze is only used in winter, but in fact, antifreeze should be used all year round.
As an average car owner who enjoys tinkering with vehicles, coolant colors function like traffic signals to distinguish different types. Green typically indicates traditional formulas, such as silicate-based ones, which are better suited for older engines—they offer strong corrosion resistance but need replacement every two years or so to prevent scaling and clogging. Red or orange coolants, on the other hand, are mostly OAT (Organic Acid Technology) types with a longer lifespan of up to five years, compatible with modern aluminum components. Mixing different colors may trigger chemical reactions—like my neighbor’s Volkswagen, which developed foaming and leaks after adding green fluid incorrectly. In reality, colors are manufacturers’ codes to help us avoid mistakes at a glance. Always refer to your vehicle’s manual for the safest color choice—never underestimate this small detail for safe driving.
